1. Field of the Invention
The invention relates to an electronic package, and more particularly, to an electronic package with a central protrusion on the substrate.
2. Description of the Related Art
As electronic products are getting smaller and lighter, the packages for protecting and interconnecting IC chips also have the same trend. With ever-increasing demands for miniaturization and higher operating speeds, multi-chip packages have become an attractive approach in a variety of electronic device. Multi-chip packages, which contain two or more chips in a single package, can help minimize the limitation in system operation speed. In addition, multi-chip packages are capable of decreasing the interconnection length between IC chips thereby reducing signal delays and access times.
Referring to FIG. 1, a conventional stacked package includes a first substrate 100, a second chip 110, a passive component 112, a first sealant 120, a second substrate 130, a plurality of bonding wires 140, a second sealant 150 and a first chip 160. A plurality of first bonding pads 102 is disposed on the upper surface 100a of the first substrate 100 and a plurality of metal bumps 104 is attached to the lower surface 100b of the first substrate 100. The second chip 110 and passive component 112 are disposed on the upper surface 100a of the first substrate 100 and are electrically connected to the first bonding pads 102 by bonding wires 114 and conductive blocks 116 respectively. The first sealant 120 is formed on the upper surface 100a of the first substrate 100 to encapsulate the second chip 110 and passive component 112. The lower surface 130b of the second substrate 130 is attached to the first sealant 120 and a plurality of second bonding pads 136 is disposed on the upper surface 130a of the second substrate 130. The bonding wires 140 electrically connect the second bonding pads 136 to the first bonding pads 102. The second sealant 150 is formed on the upper surface 100a of the first substrate 100 and on the upper surface 130a of the second substrate 130 to encapsulate the bonding wires 140, the first sealant 120 and the second bonding pads 136. The first chip 160 and passive component 112 are positioned on the upper surface 130a of the second substrate 130 and electrically connected to the second bonding pads 136 by conductive blocks 162.
In the above stacked package, it is necessary for the second sealant 150 to protrude from the second substrate 130 so as to totally encase the bonding wires 140 which are used to electrically connect the second substrate 130 to the first substrate 100. Therefore, the mold for forming the sealant 150 is very special so that the resulting sealant 150 can totally encase the bonding wires 140. Such special mold is much expensive and thus leads to the increase in production cost.
Accordingly, there exists a need to provide an electronic package to solve the above-mentioned problems.